Change the ownership of power_supply structure from each driver
implementing the class to the power supply core.
The patch changes power_supply_register() function thus all drivers
implementing power supply class are adjusted.
Each driver provides the implementation of power supply. However it
should not be the owner of power supply class instance because it is
exposed by core to other subsystems with power_supply_get_by_name().
These other subsystems have no knowledge when the driver will unregister
the power supply. This leads to several issues when driver is unbound -
mostly because user of power supply accesses freed memory.
Instead let the core own the instance of struct 'power_supply'. Other
users of this power supply will still access valid memory because it
will be freed when device reference count reaches 0. Currently this
means "it will leak" but power_supply_put() call in next patches will
solve it.
This solves invalid memory references in following race condition
scenario:
Thread 1: charger manager
Thread 2: power supply driver, used by charger manager
THREAD 1 (charger manager) THREAD 2 (power supply driver)
========================== ==============================
psy = power_supply_get_by_name()
Driver unbind, .remove
power_supply_unregister()
Device fully removed
psy->get_property()
The 'get_property' call is executed in invalid context because the driver was
unbound and struct 'power_supply' memory was freed.
This could be observed easily with charger manager driver (here compiled
with max17040 fuel gauge):
$ cat /sys/devices/virtual/power_supply/cm-battery/capacity &
$ echo "1-0036" > /sys/bus/i2c/drivers/max17040/unbind
[ 55.725123] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 55.732584] pgd = d98d4000
[ 55.734060] [00000000] *pgd=5afa2831, *pte=00000000, *ppte=00000000
[ 55.740318] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
[ 55.746210] Modules linked in:
[ 55.749259] CPU: 1 PID: 2936 Comm: cat Tainted: G W 3.19.0-rc1-next-20141226-00048-gf79f475f3c44-dirty #1496
[ 55.760190] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 55.766270] task: d9b76f00 ti: daf54000 task.ti: daf54000
[ 55.771647] PC is at 0x0
[ 55.774182] LR is at charger_get_property+0x2f4/0x36c
[ 55.779201] pc : [<00000000>] lr : [<c034b0b4>] psr: 60000013
[ 55.779201] sp : daf55e90 ip : 00000003 fp : 00000000
[ 55.790657] r10: 00000000 r9 : c06e2878 r8 : d9b26c68
[ 55.795865] r7 : dad81610 r6 : daec7410 r5 : daf55ebc r4 : 00000000
[ 55.802367] r3 : 00000000 r2 : daf55ebc r1 : 0000002a r0 : d9b26c68
[ 55.808879] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
[ 55.815994] Control: 10c5387d Table: 598d406a DAC: 00000015
[ 55.821723] Process cat (pid: 2936, stack limit = 0xdaf54210)
[ 55.827451] Stack: (0xdaf55e90 to 0xdaf56000)
[ 55.831795] 5e80: 60000013 c01459c4 0000002a c06f8ef8
[ 55.839956] 5ea0: db651000 c06f8ef8 daebac00 c04cb668 daebac08 c0346864 00000000 c01459c4
[ 55.848115] 5ec0: d99eaa80 c06f8ef8 00000fff 00001000 db651000 c027f25c c027f240 d99eaa80
[ 55.856274] 5ee0: d9a06c00 c0146218 daf55f18 00001000 d99eaa80 db4c18c0 00000001 00000001
[ 55.864468] 5f00: daf55f80 c0144c78 c0144c54 c0107f90 00015000 d99eaab0 00000000 00000000
[ 55.872603] 5f20: 000051c7 00000000 db4c18c0 c04a9370 00015000 00001000 daf55f80 00001000
[ 55.880763] 5f40: daf54000 00015000 00000000 c00e53dc db4c18c0 c00e548c 0000000d 00008124
[ 55.888937] 5f60: 00000001 00000000 00000000 db4c18c0 db4c18c0 00001000 00015000 c00e5550
[ 55.897099] 5f80: 00000000 00000000 00001000 00001000 00015000 00000003 00000003 c000f364
[ 55.905239] 5fa0: 00000000 c000f1a0 00001000 00015000 00000003 00015000 00001000 0001333c
[ 55.913399] 5fc0: 00001000 00015000 00000003 00000003 00000002 00000000 00000000 00000000
[ 55.921560] 5fe0: 7fffe000 be999850 0000a225 b6f3c19c 60000010 00000003 00000000 00000000
[ 55.929744] [<c034b0b4>] (charger_get_property) from [<c0346864>] (power_supply_show_property+0x48/0x20c)
[ 55.939286] [<c0346864>] (power_supply_show_property) from [<c027f25c>] (dev_attr_show+0x1c/0x48)
[ 55.948130] [<c027f25c>] (dev_attr_show) from [<c0146218>] (sysfs_kf_seq_show+0x84/0x104)
[ 55.956298] [<c0146218>] (sysfs_kf_seq_show) from [<c0144c78>] (kernfs_seq_show+0x24/0x28)
[ 55.964536] [<c0144c78>] (kernfs_seq_show) from [<c0107f90>] (seq_read+0x1b0/0x484)
[ 55.972172] [<c0107f90>] (seq_read) from [<c00e53dc>] (__vfs_read+0x18/0x4c)
[ 55.979188] [<c00e53dc>] (__vfs_read) from [<c00e548c>] (vfs_read+0x7c/0x100)
[ 55.986304] [<c00e548c>] (vfs_read) from [<c00e5550>] (SyS_read+0x40/0x8c)
[ 55.993164] [<c00e5550>] (SyS_read) from [<c000f1a0>] (ret_fast_syscall+0x0/0x48)
[ 56.000626] Code: bad PC value
[ 56.011652] ---[ end trace 7b64343fbdae8ef1 ]---
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
[for the nvec part]
Reviewed-by: Marc Dietrich <marvin24@gmx.de>
[for compal-laptop.c]
Acked-by: Darren Hart <dvhart@linux.intel.com>
[for the mfd part]
Acked-by: Lee Jones <lee.jones@linaro.org>
[for the hid part]
Acked-by: Jiri Kosina <jkosina@suse.cz>
[for the acpi part]
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Add new structure 'power_supply_config' for holding run-time
initialization data like of_node, supplies and private driver data.
The power_supply_register() function is changed so all power supply
drivers need updating.
When registering the power supply this new 'power_supply_config' should be
used instead of directly initializing 'struct power_supply'. This allows
changing the ownership of power_supply structure from driver to the
power supply core in next patches.
When a driver does not use of_node or supplies then it should use NULL
as config. If driver uses of_node or supplies then it should allocate
config on stack and initialize it with proper values.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
[for the nvec part]
Reviewed-by: Marc Dietrich <marvin24@gmx.de>
[for drivers/platform/x86/compal-laptop.c]
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
[for drivers/hid/*]
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_HOTPLUG is going away as an option so __devinit is no longer
needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With devm_kzalloc there is no need of freeing at the errorpath and also
at unregister it.
Signed-off-by: Devendra Naga <develkernel412222@gmail.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
module_platform_driver can be used to replace the platform_driver
register and unregister functions, with the calls to module_init
and module_exit,
i.e. all the code that is doing like the below
static int __init mymod_init(void)
{
return platform_driver_register(&drv_operations);
}
static void __exit mymod_exit(void)
{
platform_driver_unregister(&drv_operations);
}
module_init(mymod_init);
module_exit(mymod_exit);
can be replaced with
module_platform_driver(drv_operations)...
Signed-off-by: Devendra Naga <develkernel412222@gmail.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
all pretty straightforward, except one thing.
One of our patches added thermal support for power supply class, but
thermal/ subsystem changed under our feet. We (well, Stephen, that is)
caught the issue and it was decided[1] that I'd just delay the battery
pull request, and then will fix it up by merging upstream back into
battery tree at the specific commit.
That's not all though: another[2] small fixup for thermal subsystem was
needed to get rid of a warning in power supply subsystem (the warning
was not drivers/power's "fault", the thermal registration function just
needed a proper const annotation, which is also done by a small commit
on top of the merge.
So, to sum this up:
- The 'master' branch of the battery tree was in the -next tree for
weeks, was never rebased, altered etc. It should be all OK;
- Although, for-v3.6 tag contains the 'master' branch + merge + the
warning fix.
[1] http://lkml.org/lkml/2012/6/19/23
[2] http://lkml.org/lkml/2012/6/18/28
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Merge tag 'for-v3.6' of git://git.infradead.org/battery-2.6
Pull battery updates from Anton Vorontsov:
"The tag contains just a few battery-related changes for v3.6. It's is
all pretty straightforward, except one thing.
One of our patches added thermal support for power supply class, but
thermal/ subsystem changed under our feet. We (well, Stephen, that
is) caught the issue and it was decided[1] that I'd just delay the
battery pull request, and then will fix it up by merging upstream back
into battery tree at the specific commit.
That's not all though: another[2] small fixup for thermal subsystem
was needed to get rid of a warning in power supply subsystem (the
warning was not drivers/power's "fault", the thermal registration
function just needed a proper const annotation, which is also done by
a small commit on top of the merge.
So, to sum this up:
- The 'master' branch of the battery tree was in the -next tree for
weeks, was never rebased, altered etc. It should be all OK;
- Although, for-v3.6 tag contains the 'master' branch + merge + the
warning fix.
[1] http://lkml.org/lkml/2012/6/19/23
[2] http://lkml.org/lkml/2012/6/18/28"
* tag 'for-v3.6' of git://git.infradead.org/battery-2.6: (23 commits)
thermal: Constify 'type' argument for the registration routine
olpc-battery: update CHARGE_FULL_DESIGN property for BYD LiFe batteries
olpc-battery: Add VOLTAGE_MAX_DESIGN property
charger-manager: Fix build break related to EXTCON
lp8727_charger: Move header file into platform_data directory
power_supply: Add min/max alert properties for CAPACITY, TEMP, TEMP_AMBIENT
bq27x00_battery: Add support for BQ27425 chip
charger-manager: Set current limit of regulator for over current protection
charger-manager: Use EXTCON Subsystem to detect charger cables for charging
test_power: Add VOLTAGE_NOW and BATTERY_TEMP properties
test_power: Add support for USB AC source
gpio-charger: Use cansleep version of gpio_set_value
bq27x00_battery: Add support for power average and health properties
sbs-battery: Don't trigger false supply_changed event
twl4030_charger: Allow charger to control the regulator that feeds it
twl4030_charger: Add backup-battery charging
twl4030_charger: Fix some typos
max17042_battery: Support CHARGE_COUNTER power supply attribute
smb347-charger: Add constant charge and current properties
power_supply: Add constant charge_current and charge_voltage properties
...
This patch fixes the following sparse warning:
CHECK drivers/power/ds2781_battery.c
drivers/power/ds2781_battery.c:72:5: warning: symbol 'w1_ds2781_read' was not declared. Should it be static?
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
The 'mutex' in struct w1_master is use for two very different
purposes.
Firstly it protects various data structures such as the list of all
slaves.
Secondly it protects the w1 buss against concurrent accesses.
This can lead to deadlocks when the ->probe code called while adding a
slave needs to talk on the bus, as is the case for power_supply
devices.
ds2780 and ds2781 drivers contain a work around to track which
process hold the lock simply to avoid this deadlock. bq27000 doesn't
have that work around and so deadlocks.
There are other possible deadlocks involving sysfs.
When removing a device the sysfs s_active lock is held, so the lock
that protects the slave list must take precedence over s_active.
However when access power_supply attributes via sysfs, the s_active
lock must take precedence over the lock that protects accesses to
the bus.
So to avoid deadlocks between w1 slaves and sysfs, these must be
two separate locks. Making them separate means that the work around
in ds2780 and ds2781 can be removed.
So this patch:
- adds a new mutex: "bus_mutex" which serialises access to the bus.
- takes in mutex in w1_search and ds1wm_search while they access
the bus for searching. The mutex is dropped before calling the
callback which adds the slave.
- changes all slaves to use bus_mutex instead of mutex to
protect access to the bus
- removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the
related code from drivers/power/ds278[01]_battery.c which
calls them.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since we have defined DS2781_PARAM_EEPROM_SIZE and
DS2781_USER_EEPROM_SIZE, use them to simplify the code.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
